Morphological variation under domestication: how variable are chickens?. Issue 8 (8th August 2018)

• Record Type: Journal Article
• Authors: Stange, Madlen; Núñez-León, Daniel; Sánchez-Villagra, Marcelo R.; Jensen, Per; Wilson, Laura A. B.
• Is Part Of: Royal Society open science. Volume 5:Issue 8(2018)
• Publication Date: 2018-08-08
• Subjects: skull -- modularity -- morphological integration -- neural crest -- fowl -- morphological diversity; Science -- Periodicals; 500
• DOI: 10.1098/rsos.180993
• Languages: English
• ISSNs: 2054-5703

Abstract

Abstract : The process of domestication has long fascinated evolutionary biologists, yielding insights into the rapidity with which selection can alter behaviour and morphology. Previous studies on dogs, cattle and pigeons have demonstrated that domesticated forms show greater magnitudes of morphological variation than their wild ancestors. Here, we quantify variation in skull morphology, modularity and integration in chickens and compare those to the wild fowl using three-dimensional geometric morphometrics and multivariate statistics. Similar to other domesticated species, chickens exhibit a greater magnitude of variation in shape compared with their ancestors. The most variable part of the chicken skull is the cranial vault, being formed by dermal and neural crest-derived bones, its form possibly related to brain shape variation in chickens, especially in crested breeds. Neural crest-derived portions of the skull exhibit a higher amount of variation. Further, we find that the chicken skull is strongly integrated, confirming previous studies in birds, in contrast to the presence of modularity and decreased integration in mammals.